The Glacialtech Igloo 5610 Silent heatsink is identical
the Igloo 5610 PWM model in all ways, except that the two coolers use different fans.
The Igloo 5610 Silent that Frostytech is testing in this review
has a nice and quiet fixed-speed fan, the previous model a louder PWM fan. Both
heatsinks are compact LGA775 compatible CPU coolers and suitable for office PCs.

Glacialtech's Igloo 5610 Silent is a simple heatsink, economically priced and quiet running
as its name suggests. According to Frostytech's real world measurements,
it produces less than 45 dBA. The cooler is comprised of two
heatpipes, a small section of extruded aluminum heatsink and a short array of
aluminum cooling fins. It weighs a feathery 373 grams, and ships
with a pre-applied patch of thermal compound on its base.

The only odd thing with the Glacialtech
Igloo 5610 series is the manufacturer's choice of using screw-based clips. For a heatsink this
light, we would have expected the standard Intel push-to-click plastic retention mechanisms. Instead
with the Igloo 5610 Silent we
find four captive screws and a metal rear-motherboard support bracket which necessitates removing
the board from the PC chassis. For a heatsink that
weighs 373grams, that comes with pre-applied thermal compound, and that is best
suited towards generic office PCs, this isn't convenient.

For system integrators,
or industrial PC applications a screw based heatsink retention mechanism
fits the bill. Perhaps that is the intended application here... Anyway, let's begin the
analysis of the Glacialtech Igloo 5610 Silent heatsink.

The Glacialtech
Igloo 5610 Silent heatsink is a pretty straightforward CPU cooler. Only after removing
the 80mm fan do we see one of its unique qualities - scalloped cooling fins. Seen
from the top down, the leading edge of each aluminum fin has a little wavy
pattern punched out of it. This helps break up laminar air flow and decrease
back pressure as the air exits the fan and proceeds through the array of
aluminum cooling fins which are press-fit around the heatpipes. The heatpipes
are soldered to the copper base, but not each individual aluminum
fin.

FrostyTech's Test Methodologies are outlined in detail here if you care to know what equipment is
used, and the parameters under which the tests are conducted. Now let's move
forward and take a closer look at this heatsink, its acoustic characteristics,
and of course its performance in the thermal tests!

The Heatsink
Fan: The 80x80x25mm
fan rotates at a speed of 1800RPM and doesn't generate that much in the way of noise. The Glacialtech
Igloo 5610 Silent draws power from a standard 3-pin motherboard
fan header. The eleven-blade impeller doesn't have a wire fan grill
protecting it, so make sure errant wires are well clear of the blades.

Heatsink Top:Looking from the top down, the Glacialtech
Igloo 5610 Silent heatsink has a compact profile that is 64mm deep. Two 6mm diameter
U-shapped heatpipes poke out from the top on either side. The fan is attached to
an aluminum fan shroud which wraps around the top of the cooler to create a small
plenum in front of the raw aluminum fins.

Heatsink Side
A: Viewed from the
side we have a better idea of how simple the Glacialtech Igloo 5610 Silent heatsink
is. Two 6mm diameter heatpipes, a 62mm high section of aluminum fins,
a small extruded heatsink below this and a thin copper base. Each aluminum fin is 0.31mm thick and
spaced 1.2mm from the next. The fins are press-fit over the heatpipes, not soldered. Note
the white cups which hold each of the four mounting screws.

Heatsink Side B: From the rear the Glacialtech Igloo 5610 Silent heatsink
presents an unimpeded route for air to flow through. The little extruded
heatsink looks like something used on chipsets, it's essentially 50 x
21.5 x 37mm in size and forms the base of the entire cooler. Square recesses are machined in
its base for the heatpipes to pass through, and on top of
them is the copper base plate. Its fins are
0.75mm thick at the base, spaced 1.15mm apart.

Heatsink Base:
The base of the Glacialtech Igloo
5610 Silent heatsink consists of a small 34x32.75mm square of nickel plated copper base. The base is 2mm
thick, but is soldered to the heatpipes and rest of the heatsink chassis. The base has a smooth
surface finish with a roughness of ~16 microinches or better, and is quite flat. The heatsink ships from
the factory with a pre-applied patch of thermal compound. Each for
the four mounting screws is held captive in the little white cups so they
won't fall out during the installation procedure.